Re: NULL as the empty string

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: NULL as the empty string
Date	2017-11-21 15:28 -0800
Organization	None to speak of
Message-ID	<lntvxntdo5.fsf@kst-u.example.com> (permalink)
References	<ov2an8$7sq$1@dont-email.me> <NULL-20171122000000@ram.dialup.fu-berlin.de>

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ram@zedat.fu-berlin.de (Stefan Ram) writes:
> jacobnavia <jacob@jacob.remcomp.fr> writes:
>>Whaat would happen if we decide to give meaning to NULL?
>
>   One can do so by
>
> #include <stddef.h>
>
>   .
>
>>strlen would return zero, etc. This way, we would save terabytes of "\0" 
>>strings since an empty string would not require any storage, since it is 
>>empty of course!
>
>   An implementation already is free to map all »""« to the same address.
>
>       »It is unspecified whether these arrays are distinct
>       provided their elements have the appropriate values.«
>
>     6.4.5p7

Yes, but there's a difference between an empty string and an empty
string literal.

This:

    char s[] = "";

creates an empty string.  The address of s won't be the same as the address
of an empty string literal (unless there's some interesting optimization
going on).

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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Thread

NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-21 23:52 +0100
  Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 15:16 -0800
    Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:38 +0100
      Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:02 -0800
        Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:13 +0100
          Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:52 -0800
      Re: NULL as the empty string Robert Wessel <robertwessel2@yahoo.com> - 2017-11-21 18:09 -0600
      Re: NULL as the empty string Siri Cruise <chine.bleu@yahoo.com> - 2017-11-21 16:34 -0800
      Re: NULL as the empty string David Brown <david.brown@hesbynett.no> - 2017-11-22 12:12 +0100
    Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 15:57 -0800
      Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:06 +0100
        Re: NULL as the empty string supercat@casperkitty.com - 2017-11-22 15:42 -0800
          Re: NULL as the empty string Melzzzzz <Melzzzzz@zzzzz.com> - 2017-11-22 23:49 +0000
            Re: NULL as the empty string supercat@casperkitty.com - 2017-11-22 15:56 -0800
              Re: NULL as the empty string Melzzzzz <Melzzzzz@zzzzz.com> - 2017-11-23 00:06 +0000
                Re: NULL as the empty string supercat@casperkitty.com - 2017-11-23 17:31 -0800
                Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-24 09:42 +0100
                Re: NULL as the empty string supercat@casperkitty.com - 2017-11-24 13:47 -0800
    Re: NULL as the empty string Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-11-22 06:46 +0000
  Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 15:17 -0800
    Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:26 +0100
      Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 16:03 -0800
  Re: NULL as the empty string "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-11-22 00:27 +0100
    Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:42 +0100
      Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:05 -0800
  Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 15:28 -0800
  Re: NULL as the empty string Thiago Adams <thiago.adams@gmail.com> - 2017-11-21 16:04 -0800
  Re: NULL as the empty string Siri Cruise <chine.bleu@yahoo.com> - 2017-11-21 16:25 -0800
    Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:34 +0100
  Re: NULL as the empty string bartc <bc@freeuk.com> - 2017-11-22 00:36 +0000
  Re: NULL as the empty string Öö Tiib <ootiib@hot.ee> - 2017-11-21 23:07 -0800
  NULL as the empty string asetofsymbols@gmail.com - 2017-11-23 22:23 -0800

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